JP2001333423A - Dark place monitoring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a monitoring camera that causes no uneven luminance of an infrared LED for lighting even when the direction of the supervisory camera is vertically changed. SOLUTION: LEDs 4a-4d are placed at both sides of a lens 2 of the supervisory camera 1, and infrared rays from the LEDs 4a-4d illuminate an object to pick up its image. When the camera 1 is directed upward (held in nearly horizontal direction), since the lighting path of the upper stage LEDs is decreased more than that of the lower stage, the current of the upper stage LED 4a is decreased and when the camera is directed downward, since the lighting path of the lower stage LED is decreased, the current of the lower stage LED 4d is decreased so as to eliminate uneven luminance thereby eliminating solid whitening of an image due to excess lighting, enhancing a sensor function and reducing useless power consumption due to useless lighting.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dark place monitoring apparatus, which controls the current of an infrared LED (Light Emitting Diode, hereinafter referred to as LED) in accordance with the direction of a monitoring camera to reduce uneven illumination of a subject. About.

[0002]

2. Description of the Related Art In a dark place monitoring apparatus, for example, as shown in FIG.
There is an arrangement in which 4a to 4d are arranged to emit an infrared ray to irradiate a subject so that an image can be captured even in a dark monitoring area. However, when the LEDs 4a to 4d are lit at the same current value, the subject is not uniformly illuminated due to the difference in the distance to the subject, causing uneven illuminance. In some cases, the state (distribution) of uneven illuminance may be different. An overexposed portion of the image occurs in a portion where the illuminance is high, which causes a decrease in the image sensor function of the dark place monitoring device. Further, when the illuminance is too high, power is wasted.

[0003]

SUMMARY OF THE INVENTION In view of the above, the present invention controls a current of an LED according to an angle of a surveillance camera when the vertical angle of the surveillance camera is changed, thereby reducing uneven illuminance of a subject to provide a sensor function. And at the same time, to reduce unnecessary power consumption.

[0004]

In order to achieve the above object, in a dark place monitoring apparatus according to the present invention, a plurality of LEDs are arranged around a lens of a monitoring camera, a subject is irradiated, and monitoring is performed by imaging. A camera angle setting unit for setting an angle of the monitoring camera, a storage unit for storing a current value applied to each LED in association with the angle of the monitoring camera, and a camera angle setting unit based on data read from the storage unit. A discriminating unit for discriminating data corresponding to the camera angle set in step 1, a lighting control unit for controlling the current of each LED based on a signal from the discriminating unit; The control unit controls the irradiation intensity of each LED according to the setting of the angle of the surveillance camera, and suppresses uneven illuminance of the subject.

In this case, the elevation angle of the surveillance camera is set by the camera angle setting unit, and the current value of each LED is stored in the storage unit in correspondence with the elevation angle of the surveillance camera. The camera angle setting unit may set the elevation angle of the surveillance camera in a plurality of predetermined steps, and store the current value of each LED in the storage unit in association with each elevation angle of the surveillance camera.

A plurality of LEDs are arranged vertically on both sides of the lens of the surveillance camera, and the current value of the LEDs is stored in the storage unit for each stage. The current value of the LED of each stage set for each elevation angle of the monitoring camera is stored in the storage unit.

[0007] The current value of the infrared LED of each stage stored in the storage unit is smaller in the upper stage than in the lower stage when the surveillance camera is upward, and is smaller in the lower stage than in the upper stage when the surveillance camera is downward. Then, the illuminance of the subject is made uniform.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described based on embodiments with reference to the drawings. FIG. 1 is a front view of a main part of an example of a dark place monitoring apparatus according to the present invention, and FIG. 2 is a block diagram of a main part of one embodiment of a dark place monitoring apparatus according to the present invention. 1 is a monitoring camera, 2 is a lens, 3 is a substrate, and 4a to 4d are LEDs. 2, a camera angle setting unit 11 for setting the elevation angle of the monitoring camera 1, a storage unit 12 for storing a current value applied to the LEDs 4 a to 4 d of the LED lighting unit 15 in association with the angle of the monitoring camera 1, and a storage unit 13. A discriminating unit for discriminating data corresponding to the elevation angle set by the camera angle setting unit 11 from the data read from the storage unit 12, and LEDs (4 a to 4 d) of the LED lighting unit 15 based on a signal from the discriminating unit 13. Lighting control unit to control the current of
Reference numeral 16 denotes a control unit that controls each unit.

Next, the operation of the dark place monitoring apparatus according to the present invention will be described. In order to irradiate the subject with infrared light, for example, four LEDs are provided on both sides of the lens 2 of the monitoring camera 1, respectively.
4a to 4d are provided. For example, as shown in FIG. 3, the surveillance camera 1 raises the elevation angle in a plurality of steps from (a) upward (substantially horizontal) to (b) downward as shown in FIG. Can be changed to In the case of the upward direction as shown in FIG.
The current of the upper LED 4a, which is shorter than the ED 4d, is reduced, and if it is downward as in (b), the current of the lower LED 4d is reduced.

For this reason, the current values of the LEDs 4a, 4b, 4c, and 4d are stored in the storage unit 12 in correspondence with the elevation angles (a plurality of angles) of the surveillance camera. When the angle (elevation angle) of the camera is changed, the determination unit 13 uses the data read from the storage unit 12 via the control unit 16 to
The data corresponding to the elevation angle from the camera angle setting unit 11 is determined, and the illumination control unit 14 performs LE based on the determined data.
By controlling the current of each of the LEDs 4a to 4d of the D lighting unit 15, FIG.
As in the examples shown in (a) and (b), the irradiation intensity of each LED is controlled. In the example of FIG. 3, only the uppermost LED 4a and the lowermost LED 4d are shown as being changed. Make the irradiation intensity uniform. As a result, unevenness in illuminance of the subject is reduced, adverse effects such as the occurrence of overexposure of an image in a portion where illumination is too strong are eliminated, and the sensor function can be improved, and at the same time, wasteful consumption of power can be suppressed.

[0011]

As described above, according to the dark place monitoring apparatus of the present invention, when the angle (elevation angle) of the surveillance camera is changed, the current value of each stage LED is preset according to the angle. Value, and the illuminance non-uniformity of the subject is reduced.Therefore, there is no adverse effect such as an image being overexposed due to too strong illumination, and the image sensor function is improved, and at the same time wasteful power consumption is achieved. Can be suppressed.

[Brief description of the drawings]

FIG. 1 is a front view of a main part of an embodiment of a dark place monitoring device according to the present invention.

FIG. 2 is a main part block diagram of an embodiment of a dark place monitoring device according to the present invention.

FIG. 3 is an example of a relationship between an elevation angle of a monitoring camera and an irradiation intensity of an LED.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Surveillance camera 2 Lens 3 Substrate 4a-4d Infrared LED 11 Camera angle setting part 12 Storage part 13 Discrimination part 14 Lighting control part 15 LED lighting part 16 Control part

Claims (6)

[Claims] 1. A camera angle setting unit for arranging a plurality of infrared LEDs around a lens of a surveillance camera, illuminating a subject, and monitoring by imaging, wherein a camera angle setting unit for setting an angle of the surveillance camera; A storage unit for storing a current value applied to the infrared LED in association with the angle of the monitoring camera;
A determining unit that determines data corresponding to the camera angle set by the camera angle setting unit in the data read from the storage unit, an illumination control unit that controls the current of each infrared LED based on a signal from the determining unit, The camera angle setting unit, the storage unit, the discrimination unit, and a control unit that controls the illumination control unit, and controls the irradiation intensity of each infrared LED according to the setting of the angle of the surveillance camera, thereby suppressing uneven illuminance of the subject. Dark place monitoring device. 2. The darkness according to claim 1, wherein an elevation angle of the monitoring camera is set by the camera angle setting section, and a current value of each infrared LED is stored in the storage section in correspondence with the elevation angle of the monitoring camera. Station monitoring equipment. 3. The elevation angle of the surveillance camera is set in a plurality of predetermined steps by the camera angle setting section, and the current value of each infrared LED is stored in the storage section in correspondence with each elevation angle of the surveillance camera. The dark place monitoring device according to claim 1. 4. A dark place monitoring system according to claim 3, wherein said infrared LEDs are arranged in a plurality of stages vertically on both sides of the lens of the surveillance camera, and the current value of the infrared LEDs is stored in the storage unit for each stage. apparatus. 5. The dark place monitoring apparatus according to claim 4, wherein the storage unit stores the current values of the infrared LEDs of each stage set for each elevation angle of the monitoring camera. 6. An infrared ray L of each stage stored in the storage unit.
5. The current value of the ED is such that when the surveillance camera is upward, the upper stage is smaller than the lower stage, and when the surveillance camera is downward, the lower stage is smaller than the upper stage so that the illuminance of the subject is uniform. Or the dark place monitoring device according to 5.